Volcanoes Seen From Space and the Eruption Update for October 6, 2011

So, last week’s combination of a bunch of great images of volcanoes from space with the Smithsonian/USGS Global Volcanism Program’s Weekly Volcanic ActivityReport went over so well, I thought I’d try it again. I’m having trouble coming up with a catchy name for this feature, so if you have any ideas, leave them in the comments below. As ever, special thanks to Sally Kuhn Sennert for putting together the weekly report over at the GVP and the NASA Earth Observatory for the amazing images taken from orbit.

Last week I mentioned that I couldn’t find any images of Lewotobi in Indonesia in the NASA EO archive. Well, leave it to them to go and find me some images of the volcano in question, along with a couple other great gems.

Above:

Flores Island

This is the Isle of Flores in Indonesia, one of main islands of the nation. It isn’t known for its volcanoes but it does have a few, including Lewotobi and Kelimutu (see both above). Flores is, at least right now, most known for the rare species of human that apparently lived on the island from ~17,000 to 9,500 years ago — Homo floresiensis, the famous “Hobbit” fossils. Now, there is still debate over the true place that Homo floresiensis has on the family tree of humans, but so far, they have only been found on Flores.

Image: Flores Island in Indonesia seen in 2001. Lewotobi can be seen on the far right of the image. (NASA Earth Observatory)

Lewotobi Volcanoes

Lewotobi, mentioned in last week’s GVP Report, is actually a twin volcano, colloquially referred to as the “husband and wife” — Lewotobi Perempuan and Lewotobi Lakilaki. You can see in the image that Lakilaki is actually a parasitic cone on the flanks of the larger Perempaun edifice and seems to have younger volcanic deposits (grey) coming from its vent over the buff-colored material on the slopes of Perempuan. If you look at the eruptive history, that observatory would be correct, as Lakilaki was the focus of activity during the last eruption at Lewotobi in 2003. In fact, the last known eruption from the Perempuan crater was all the way back in 1935. This is definitely not uncommon behavior at a volcano, so change the center of activity across localized vents, something we’ve seen often at places like Kirishima and Kilauea.

Kelimutu

Kelimutu is another one of the active volcanoes on Flores and as this image shows, it looks like this volcano has no less than four craters at its summit, three of which had obvious crater lakes in 2009 — these three volcanic lakes are popular tourist destinations. There isn’t much known about the volcanic history of Kelimutu, but the last activity was in 1968 and along with the two other known historic eruption, was a small phreatic (steam-driven) explosion.

Image: Anak Krakatau and the ancestral Krakatau caldera within the Sunda Strait, Indonesia, seen in May 2002. (NASA Earth Observatory)

Villarrica

Chile:Villarrica has had an active lava lake in the crater for quite a few years and when I visited Pucón in 2004, you could easily see the glow of the crater from the town. Activity looks to be ramping up at the volcano, with a rapid rise in the lava lake level causing melting of the snow and ice at the summit, along with dusting of the slopes with ash. This was followed by some strombolian explosions at the summit crater and threw ash and bombs onto the upper slopes. This 2010 image of Villarrica shows the snow-covered slopes along with paths that occasional lahars take down the river valleys that head away from the volcano like spider legs. Thanks to its location near Pucón, there are a number of webcams that you can watch to see the activity, provided that the cloud cover allows a clear view.

Image: Villarrica in Chile seen May 2010. (NASA Earth Observatory)

Santa María

Guatemala:This week’s activity at Santa María’s Santiaguito dome produced explosions, which is common at this dome complex as the oversteepened domes collapse and produce block-and-ash flows. You can see the paths of some of these flows on the 2002 NASA EO images of Santa María — along with the somewhat startling juxtaposition of the volcano and the city of Quezaltenango (home of the famed Guatemalan Insanity Peppers). If you mix the volcanic debris with water, you can easily produce lahars that can travel far afield from the volcano and that happened this week at Santa María — and the lahar moved blocks up to 2 meters large!

Aleutian Islands

Alaska: Finally, up in Alaska, the dome growth at Cleveland continues unabated. Most of the information that Alaska Volcano Observatory has been receiving about what is going on at Cleveland is via satellite imagery, like this 2006 image of a small plume from Cleveland drifting out over the Pacific. This stretch of the Aleutians is chock full of volcanoes, many of which are on uninhabited islands, so it is difficult to set up and maintain seismic stations on all the volcanoes, even one as active as Cleveland. This leaves AVO reliant on “good seeing” from satellite visual and infrared camera to keep tabs on the volcano.

Image: An ash plume from Cleveland in the Aleutians, along with a number of other Aleutian volcanoes. (NASA Earth Observatory)